By default and after a clean Haiku installation, there are 4 menus that allow to run apps in the deskbar:
Applications
Demos
Desktop applets
Preferences
All use the same icon (folder like): I think having a different icon for each (for eg. it’s quite common in every operating system to use the Gears icon for the settings/preferences) would help distinguish each menu.
AFAIK, those menus are a stopgap solution, they are supposed to be replaced with something better anyway. My biggest gripe with them is that their localisations are broken, and they need something like categories.